Biosolids and biosolids-ash as sources of heavy metals in a plant-soil system

Citation
E. Benitez et al., Biosolids and biosolids-ash as sources of heavy metals in a plant-soil system, WATER A S P, 132(1-2), 2001, pp. 75-87
Citations number
49
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Environment/Ecology
Journal title
WATER AIR AND SOIL POLLUTION
ISSN journal
0049-6979 → ACNP
Volume
132
Issue
1-2
Year of publication
2001
Pages
75 - 87
Database
ISI
SICI code
0049-6979(2001)132:1-2<75:BABASO>2.0.ZU;2-#
Abstract
Generally, the potential for biosolids (digested or composted) to contribut e heavy metals to the soil-plant system has been compared with commercial f ertilizers and other organic wastes but not with biosolids-ash. An column s tudy was conducted in a greenhouse to determine the availability, extractab ility and leachability of metals in a degraded, non-calcareous soil amended with different biosolids (200 Mg ha(-1)). The biosolids investigated were dewatered, anaerobically digested biosolids, composted biosolids and biosol ids-ash. The columns (26 cm) were planted with wheat (Triticum aestivum L. cv Mexa). The addition of digested biosolids decreased the dry matter yield of wheat. Treatments including organic biosolids increased Cu and Zn conce ntrations in wheat roots, straw and grain, whereas the addition of biosolid s-ash did not affect the concentrations of these metals in wheat. Concentra tions of Ni, Co, Pb, Cr and Cd in wheat were below reliable detection limit s (0.06, 0.05, 0.1, 0.06 and 0.02 mg kg(-1), respectively). After harvestin g, total and AB-DTPA extractable Cu, Zn and Pb increased in the upper layer of the soil amended with the different biosolids studied, whereas levels o f AB-DTPA extractable Ni and Co were affected only when the soil was amende d with digested or composted biosolids. Total chromium increased only in tr eatments including organic biosolids. The AB-DTPA extractable Cu, Zn and Pb in the lower layer of the soil in treatments including biosolids evidenced downward movement of these metals. However, absence of these metals in col umn leachates indicates that this movement was gradual.